Bug#598308: vdr-dbg: CVE-2010-3387: insecure library loading

[Raphael Geissert]

Package: vdr-dbg
Version: 1.6.0-18
Severity: grave
Tags: security
User: team at security.debian.org
Usertags: ldpath

Hello,

During a review of the Debian archive, I've found your package to
contain a script that can be abused by an attacker to execute arbitrary
code.

The vulnerability is introduced by an insecure change to
LD_LIBRARY_PATH, and environment variable used by ld.so(8) to look for
libraries on a directory other than the standard paths.

Vulnerable code follows:

/usr/bin/vdrleaktest line 73:
LANG=C LD_LIBRARY_PATH="/usr/lib/debug;$LD_LIBRARY_PATH" \
   valgrind --tool=memcheck --leak-check=yes --num-callers=20 \
   --suppressions=/usr/share/vdr/valgrind.supp \
   /usr/bin/vdr-dbg -v $VIDEO_DIR -c $CFG_DIR -L $PLUGIN_DIR  -r $REC_CMD \
   -E $EPG_FILE -g /tmp $OPTIONS --port $SVDRP_PORT --lirc \
   "$@"

When there's an empty item on the colon-separated list of
LD_LIBRARY_PATH, ld.so treats it as '.' (i.e. CWD/$PWD.)
If the given script is executed from a directory where a potential,
local, attacker can write files to, there's a chance to exploit this
bug.

This vulnerability has been assigned the CVE id CVE-2010-3387. Please make sure
you mention it when forwarding this report to upstream and when fixing
this bug (everywhere: upstream and here at Debian.)

[0] http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-3387
[1] http://security-tracker.debian.org/tracker/CVE-2010-3387

Sincerely,
Raphael Geissert